KR20130109035A - Substrate and secondary battery - Google Patents

Abstract

PURPOSE: A substrate for a storage battery is provided to form the storage battery having a high power accumulation function by including a semiconductor layer. CONSTITUTION: A substrate comprises a semiconductor layer (1). The semiconductor layer comprises tungsten oxide powder (4) having a first peak at the range of 268-274 cm^(-1), a second peak at the range of 630-720 cm^(-1), and a third peak at the range of 800-810 cm^(-1) in Raman spectroscopic analysis. The thickness of the semiconductor layer is 1 micron or greater, and the porosity is 20-80 volume%. The BET specific surface area of the tungsten oxide powder is 0.1 m^2/g or greater on average. A storage battery (11) comprises the substrate, a counter electrode, and an electrolyte composition filled between the semiconductor layer of the substrate for the storage battery and the counter electrode.

Description

Substrate and Storage Battery {SUBSTRATE AND SECONDARY BATTERY}

<Related application>

This application is based on Japanese Patent Application No. 2012-068970 for which it applied on March 26, 2012, and claims its priority, The whole content is integrated in this specification as a reference.

Embodiment of this invention relates to the battery substrate and storage battery.

Solar cells have attracted attention as natural energy. Silicon solar cells have been the mainstream solar cells. The silicon-based solar cell realized power generation efficiency of 10% or more. On the other hand, in dye-sensitized solar cells, constant power generation efficiency is obtained by using titanium oxide powder as the electrode material.

By the way, since a solar cell literally uses sunlight, the amount of power generation changes according to the amount of sunlight. For this reason, when the amount of sunshine changes abruptly, the amount of generated power drops rapidly. Silicon-based solar cells are susceptible to changes in the amount of sunshine, and suddenly changes in the amount of electricity generate a phenomenon in which the amount of generated power suddenly becomes zero. In order to cope with this problem, there is a demand for a battery that can be efficiently stored.

An object of the present invention is to provide a storage battery substrate capable of improving a storage function and a storage battery using the same.

According to an embodiment, there is provided a battery substrate including a semiconductor layer containing tungsten oxide powder. In the tungsten oxide powder is, Raman spectroscopy, in the range of 268 to 274㎝ ^-1 in the range of the first peak, 630 ^-1 to 720㎝ a third peak in the range of the second peak, and 800 to 810㎝ ^-1 Have The thickness of a semiconductor layer is 1 micrometer or more. The porosity of the semiconductor layer is 20 vol% or more and 80 vol% or less.

Moreover, according to embodiment, the storage battery containing this battery substrate, a counter electrode, and an electrolyte composition is provided. The electrolyte composition is filled between the semiconductor layer of the battery substrate and the counter electrode.

According to the battery substrate of the said structure, an electrical storage function can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the storage battery system provided with the storage battery of embodiment.
2 is a chart showing Raman spectroscopic analysis results of the tungsten oxide powder used in the embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment is described with reference to drawings.

(1st embodiment)

According to the first embodiment, a storage battery substrate including a semiconductor layer is provided. The semiconductor layer contains a tungsten oxide powder, and the tungsten oxide powder is the first peak in the range of 268 to 274 cm ^-1 and the second peak in the range of 630 to 720 cm ^-1 in Raman spectroscopic analysis. Peak and a third peak in the range of 800 to 810 cm ⁻¹ . The semiconductor layer has a thickness of 1 µm or more and a porosity of 20 vol% or more and 80 vol% or less.

When the tungsten oxide powder has a first peak, a second peak, and a third peak, the electrical storage function of the tungsten oxide powder can be improved. However, even when the tungsten oxide powder having the first to third peaks is used, when the thickness of the semiconductor layer is less than 1 µm or the porosity of the semiconductor layer is less than 20% by volume, the electrolyte composition holding ability of the semiconductor layer is lowered. It is difficult to improve power storage performance. Moreover, even if the thickness of a semiconductor layer is 1 micrometer or more, when the porosity exceeds 80 volume%, since the amount of tungsten oxide powders is insufficient, electrical storage performance will fall. By using the tungsten oxide powder having the first to third peaks, the thickness of the semiconductor layer is in the range of 1 µm or more and the porosity is in the range of 20 to 80% by volume, whereby the electrical storage function of the tungsten oxide powder and the electrolyte composition of the semiconductor layer. Improved retention

It is preferable that the thickness of a semiconductor layer shall be 5 micrometers or more. Thereby, the electrical storage capacity of a board | substrate can be raised. The thicker the semiconductor layer is advantageous for the improvement of the electrical storage capacity. If the thickness is too thick, the permeability of the electrolyte composition may be lowered, so the upper limit of the thickness of the semiconductor layer is preferably 300 μm or less.

The range with more preferable porosity is 40 volume% or more and 70 volume% or less.

It is preferable that the average size of the space | gap of a semiconductor layer is 5 nm or more. Thereby, the uniformity of distribution of electrolyte composition at the time of holding electrolyte composition in a semiconductor layer can be improved. Moreover, the more preferable range of average size is 7 nm or more and 20 nm or less.

The BET specific surface area of the tungsten oxide powder can be 0.1 m <2> / g or more on average. Thereby, the contact area of a tungsten oxide powder and electrolyte composition can be improved. In addition, the upper limit of BET specific surface area can be made into 150 m <2> / g or less on average.

It is preferable that a film is formed in at least one part of the tungsten oxide powder surface. Materials for forming the film include inorganic substances such as metal oxides and metal nitrides, organic substances and the like. Preferred materials are Y ₂ O ₃ , TiO ₂ , ZnO, SnO ₂ , ZrO ₂ , MgO, Al ₂ O ₃ , CeO ₂ , Bi ₂ O ₃ , Mn ₃ O ₄ , Tm ₂ O ₃ , Ta ₂ O ₅ , Nb ₂ O ₅ , La ₂ O ₃ and at least one member selected from the group consisting of ITO. By forming a film on at least a part of the surface of tungsten oxide powder, the improvement of electrical storage performance can be expected. Moreover, when a metal oxide is used for a coating material, the oxygen deficiency of tungsten oxide can be reduced.

Tungsten oxide powder is manufactured by the following method, for example. First, a plasma process is performed. As the coarse powder of tungsten oxide, tungsten oxide particles having an average particle diameter of 10 m or less, preferably 1 to 5 m are prepared. If the average particle diameter of coarse powder exceeds 10 micrometers, it will become difficult to put into a plasma flame uniformly. On the other hand, when the average particle diameter is less than 1 µm, the production of coarse powder becomes difficult and causes a cost increase.

In addition, as the plasma flame, it is preferable to use a high-temperature flame having a center temperature of 8000 ° C or higher and further 10000 ° C or higher. Fine tungsten oxide particles can be obtained by heat treatment in an oxygen-containing atmosphere such as air using a high-temperature plasma flame. The tungsten oxide particles protruding from the plasma flame after being put into the plasma flame are preferably subjected to a quenching step of 1000 ° C./s or more at a distance of 1 m or more. A target tungsten oxide particle can be obtained by putting a high temperature plasma flame and performing a predetermined quenching step.

Subsequently, a heat treatment step is performed. The heat treatment step is a step of heating the tungsten oxide particles (as-plasma powder) obtained in the plasma process at a predetermined temperature in an oxidizing atmosphere for a predetermined time. The as-plasma fraction contains a large number of defects on the surface and contains several tungsten oxides with WO ₃ in which the ratio of W and O is less than 1: 3 (such as W _x O _y and y / x <3). There is a case. By adding a heat treatment step to this, while reducing surface defects, the ratio of WO ₃ in tungsten oxide is made 99% or more. Moreover, the crystal structure and the particle diameter of the tungsten oxide particle obtained can be controlled by the conditions of heat processing.

As for specific heat processing temperature (maximum temperature in a heat processing process), 300 degreeC or more and 1000 degrees C or less are good, Preferably they are 450 degreeC or more and 600 degrees C or less. The heat treatment time (holding time at the maximum temperature) is preferably 10 minutes or more, preferably 2 hours or more and 60 hours or less. This is for oxidizing slowly in the temperature range where reaction rate is small, in order to reduce defects in a particle surface and an inside. At high temperature with high reaction rate, the heat treatment time is short and there is an advantage in process cost, but as-plasma powder is not heated evenly, the crystal structure and particle size after heat treatment become uneven, or defects on the surface or inside of the particle Because it is not desirable. In particular, exceeding 1000 degreeC is unpreferable since a tungsten oxide particle produces rapid grain growth.

The oxidation atmosphere may be oxygen, inert gas, inert gas into which water or oxygen is introduced, or water. The atmospheric pressure may be atmospheric pressure or pressurized high air. Moreover, as a heating method, any of what is based on atmospheric heat conduction, radiant heat (electric furnace etc.), a high frequency, a microwave, a laser, etc. may be sufficient.

The semiconductor layer preferably includes at least one second powder selected from the group consisting of a metal oxide powder, a metal boride powder, a metal fluoride powder, a carbonate powder, a carbon powder, a metal carbide powder and a metal powder. Preferred second powders are Fe, Mn, Co, Ni, Li ₂ O, LiF, Na ₂ O, K ₂ O, MgO, CaO, MnO, MnO ₂ , FeO, Fe ₂ O ₃ , CoO, NiO, Cu ₂ O , B ₂ O ₃ , SiO ₂ , La ₂ O ₃ , ZrO ₂ , Y ₂ O ₃ , C, LaB ₆ , ITO and ATO. By using an oxide for the second powder, the sinterability of the tungsten oxide particles can be improved, and the necking bonding between the tungsten oxide and the conductive film and the tungsten oxide particles can be improved. As a result, it is possible to improve the reliability of the component by strengthening the physical bonding, and also to improve the electrical storage performance by improving the conductivity by lowering the resistance of the grain boundary. In addition, since the conductivity of the semiconductor layer can be improved by using a conductor (for example, Fe, Mn, Co, Ni, C, ITO, ATO) as the second powder, the electrical storage performance can be improved. Moreover, when the addition amount of a 2nd powder makes the total amount of a tungsten oxide powder and a 2nd powder 100 mass%, it is preferable that the addition amount of a 2nd powder is 1-10 mass%. If the addition amount is less than 1% by mass, the effect of the addition is not sufficiently obtained. When addition amount exceeds 10 mass%, there is a possibility that the addition amount is too large and the electrical storage characteristic of a tungsten oxide powder is impaired. The range with preferable addition amount is 2-6 mass%.

(Raman spectroscopic analysis)

Raman spectroscopy is carried out in the following manner. A PDP-320 manufactured by Photon Desing Co., Ltd. is used for the apparatus. The measurement conditions are brown rice Raman, measuring magnification 100 times, beam diameter of 1 μm or less, light source Ar ⁺ laser (wavelength 514.5 nm), laser power 0.5 mW (at tube), diffraction grating Single600 gr / mm, cross slit 100 μm, The slit is 100 µm and the detector CCD / Roper 1340 chnanel is used. Under these conditions, 100 to 1500 cm ^-1 are analyzed. The sample form can be measured with tungsten oxide particles.

The measuring method of the thickness, the porosity, and the average size of a semiconductor layer of a semiconductor layer is as follows.

(Thickness of semiconductor layer)

An arbitrary cross-section of at least a viewing angle of the semiconductor layer corresponding to “thickness of 1 μm or more × 10 μm in width” is formed at the upper end of the semiconductor layer (the surface on the side opposite to the surface in contact with the conductive film (in FIG. 1, the conductivity of the semiconductor layer 1). Take an enlarged picture (magnification of 5000 times or more), and take an enlarged picture 1 so as to know). In the enlarged photograph 1, the thickness of arbitrary places is measured in three places, and the average value is made into thickness (film thickness).

(Porosity of semiconductor layer)

An enlarged photograph is taken (magnification of 100,000 times or more) so that an upper end portion of the semiconductor layer can be seen at an arbitrary cross section whose viewing angle of the semiconductor layer corresponds to at least "thickness 1 µm or more x width 10 µm", and an enlarged photograph 2 is taken. From the contrast of the enlarged photograph 2, it is possible to distinguish the tungsten oxide particles and the voids. From the enlarged photograph 2, the area of the void in "unit area of 1 micrometer x 3 micrometers" is calculated | required. In addition, when it is not possible to image "unit area 1 micrometer x 3 micrometers" in one field of vision, it is assumed that imaging is performed a plurality of times until the total is "unit area 1 micrometer x 3 micrometers".

(Average size of voids in semiconductor layer)

From the enlarged photograph 2, the average size of the voids is determined by the line intercept method. Specifically, an arbitrary straight line (drawing a straight line from any end of the enlarged photograph 2) is drawn on the enlarged photograph 2, and the number of voids and the total length of the voids existing on the straight photograph are obtained. Let (the total length of voids / number of voids) be an average size, and this operation | work is performed by three arbitrary straight lines, and the average value is made into the average size of voids.

The battery substrate for an embodiment may include a support substrate such as a glass substrate and a conductive film formed on the support substrate. It is possible to form a semiconductor layer on the conductive film. The conductive film includes a transparent conductive film such as ITO or ATO. The thickness of an electrically conductive film can be 10 nm or more and 200 nm or less. In addition, a support substrate and a conductive film are not limited to a transparent thing, For example, a translucent thing etc. can be used. In addition, you may use a metal substrate as a support substrate. In the case of using a metal substrate, the back surface is insulated. In addition, it is preferable that the metal substrate be a material which is hard to corrode in an electrolyte such as titanium (Ti), ruthenium (Ru), tungsten (W), or the like. By using a metal substrate resistant to corrosion, it is not necessary to provide a conductive film like a glass substrate.

In addition, the surface of the support substrate may be roughened. By roughening the surface of a glass substrate or a metal substrate which is a support substrate, and providing a conductive film or the like thereon, the adhesion between the semiconductor layer and the conductive catalyst layer is improved. Therefore, it is preferable that Ra is 0.1-1.0 micrometer, Furthermore, 0.1-0.5 micrometer of surface roughness of a support substrate.

A semiconductor layer is formed by the method demonstrated below, for example. A paste containing tungsten oxide particles is prepared. The paste contains tungsten oxide particles, a binder, and a solvent. When tungsten oxide particles (including additives in the case of adding additives), binder and solvent are 100 wt% in total, the range of 5 to 50 wt% of tungsten oxide particles (including additives and coatings) and 3 to 30 wt% of binders Is preferably. The binder is preferably an organic binder having a thermal decomposition rate of 99.0% or more at 500 ° C. If it can thermally decompose at the temperature of 500 degrees C or less, it can prevent that a glass substrate etc. are not damaged. Ethyl cellulose, polyethylene glycol, etc. are mentioned as such a binder. Examples of the solvent include alcohols, organic solvents, pure water, and the like. In this, an alcoholic solvent is preferable.

It is preferable that mixing in paste adjustment is performed by mixing a binder and a solvent, stirring these, and then adding tungsten oxide particles and stirring them. When tungsten oxide particles and a binder are added to a solvent at once, it becomes easy to become a paste with many aggregates. In addition, when the tungsten oxide particles are fine particles having a BET surface area of 5 m 2 / g or more, sufficient agitation is necessary.

In addition, the viscosity of the paste is preferably in the range of 800 to 10000 cps at room temperature (25 ° C). The semiconductor layer is formed by applying a paste containing tungsten oxide, for example, by screen printing or the like, and baking at a temperature of 500 ° C or lower. It is effective to print a film thickness multiple times until it becomes a required thickness. Moreover, when the amount of binder is in the above range, the porosity is easily produced in the range of 20 to 80% by volume. Moreover, baking temperature shall be in the range of 200-500 degreeC, and it does not damage board | substrates, such as a glass substrate. Further, by raising the temperature raising rate to 100 deg. C / h or faster, if the binder is pyrolyzed in a short time, the average size of the voids is likely to be 5 nm or more.

Moreover, it is also effective to mix and use tungsten oxide powder from which a particle diameter differs for adjustment of a porosity. The tungsten oxide powder having a different particle diameter indicates that two or more peaks of the particle size distribution are detected when the particle size distribution is measured. By mixing small particles (small particle size powder) and large particles (large particle size powder), it is easy to adjust the porosity by introducing small particles into the gaps between the large particles.

In addition, when using and mixing tungsten oxide powder from which a particle size differs, it is preferable that the average particle diameter of a small particle size powder is 10-100 nm. Furthermore, it is preferable that it is 10-40 nm. Moreover, it is preferable that the average particle diameter of a large particle size powder is the range of 5-50 times of the average particle diameter of a small particle size powder. In addition, the mixing amount ratio is A: B = 50: 1 to 1: when the amount of the small particle powder is A parts by mass, and the amount of the large particle powder is B parts by mass, A parts by mass + B parts by mass = 100 parts by mass. It is preferable that it is ten. If it is such conditions, it will be easy to adjust the porosity of a semiconductor layer.

According to the above first embodiment of the substrate for a secondary battery described above, according to Raman spectroscopic analysis, 268 to the first peak in the range of 274㎝ ^-1, 630 to the second peak, and 800 to the range of 720㎝ ^-1 810㎝ ^{- Since the} tungsten oxide powder which has a 3rd peak in the range of ¹ , contains a semiconductor layer whose thickness is 1 micrometer or more, and a porosity is 20 volume% or more and 80 volume% or less, the electrical storage function of a tungsten oxide powder, The ability to hold the electrolyte composition of the semiconductor layer can be increased. By using this semiconductor layer, the electrical storage performance of a storage battery can be improved.

(Second Embodiment)

According to 2nd Embodiment, the storage battery containing a semiconductor electrode, a counter electrode, and an electrolyte composition is provided. The semiconductor electrode includes the storage battery substrate according to the first embodiment. The electrolyte composition is accommodated between the semiconductor electrode and the counter electrode.

An example of the storage battery system provided with the storage battery of 2nd Embodiment is shown in FIG. The storage battery system shown in FIG. 1 includes a storage battery 11 and a solar cell 14. The storage battery 11 includes a semiconductor electrode, an opposite electrode, and an electrolyte composition 3. The semiconductor electrode includes a support substrate 13 and a semiconductor layer 1 formed on the support substrate 13 through a conductive film (not shown). The semiconductor layer 1 contains tungsten oxide particles 4. The counter electrode includes a support substrate 8 such as a glass substrate, a conductive film 9 on the support substrate 8, and a conductive catalyst layer 2 formed on the conductive film 9. The space between the semiconductor electrode and the counter electrode is sealed by the sealing resin 10. The electrolyte composition 3 comprises an electrolyte solution, for example, and is filled in the space between the semiconductor layer 1 and the conductive catalyst layer 2 while being impregnated in the semiconductor layer 1. The solar cell 14 is connected with the semiconductor electrode and the counter electrode of the storage battery 11. Although the solar cell 14 is not specifically limited, For example, silicon (Si) solar cells, Copper Indium Gallium DiSelenide (CIGS) solar cells, titanium oxide (TiO ₂ ) solar cells, dye-sensitized solar cells (DSSC), etc. Can be used.

When electrons generated by the power generation of the solar cell 14 are supplied to the storage battery, ions (for example, Li ⁺ ) generated by the support electrolyte in the electrolyte composition 3 are ionized to the tungsten oxide particles 4 of the semiconductor layer 1. Since it is electrochemically reduced at the surface of), a charging reaction occurs. As the electrons accumulated in the tungsten oxide particles 4 flow to the outside, a discharge reaction occurs. The counter electrode is a positive electrode and the semiconductor electrode is a negative electrode.

According to such a storage battery system, the electrical energy generated by the generation of the solar cell 14 can be stored in the storage battery 11. When the power generation amount becomes zero due to lack of sunshine, the electric energy accumulated in the storage battery 11 can be used, and thus, even when a sudden change in weather occurs, the energy supply can be stably performed.

Hereinafter, the counter electrode and the electrolyte composition will be described.

(Counter electrode)

The counter electrode includes a support substrate 8, a conductive film 9, and a conductive catalyst layer 2. The conductive catalyst layer 2 includes, for example, a platinum (Pt) layer. In addition, a conductive organic substance can also be applied to the conductive catalyst layer 2. Polyethylenedioxythiophene (PEDOT) etc. are mentioned as a conductive organic substance. The conductive film 9 includes transparent conductive films such as ITO and ATO. The thickness of the conductive film 9 can be 10 nm or more and 200 nm or less. In addition, the support substrate 8 and the conductive film 9 are not limited to a transparent thing, For example, a translucent thing etc. can be used.

(Electrolyte composition)

The electrolyte composition 3 comprises a reversible redox pair and a supporting electrolyte.

Reversible redox pairs can be supplied, for example, from mixtures of iodine (I ₂ ) and iodide, iodide, bromide, hydroquinone, TCNQ complexes and the like. In particular, redox pairs comprising I ⁻ and I ₃ ⁻ supplied from a mixture of iodine and iodide are preferred. In addition, lithium iodide (LiI) is preferable as the iodide.

In addition, when using a mixture of iodine and iodide, it is preferable that the iodine concentration in electrolyte composition is 0.01-5 mol / L, and the iodide concentration is 0.5-5 mol / L. By carrying out the mixture of iodine and iodide in the said range, a redox reaction can be performed efficiently, the reduction of the charge transfer resistance in an electrolyte composition, and the reaction resistance in a counter electrode can be reduced.

The supporting electrolyte imparts a power storage function, for example, a lithium salt is used. Lithium salts include, for example, halogenated lithium, lithium perchlorate, lithium borate hexafluoro phosphate, lithium _{tetrafluoroborate, LiN (SO 2 Rf) 2} · LiC (SO 2 Rf) 3 ( stage, Rf = CF _3, C _{2F 5} ), LiBOB (lithium bisoxalate borate), and the like. These lithium salts can be used individually or in combination of 2 or more types. Lithium iodide is preferable at the point which can supply iodine and lithium ion.

Lithium ions ionized from lithium salts are used for charge and discharge reactions in semiconductor electrodes. If the lithium salt content in the electrolyte composition is in the range of 0.5 mol / L or more and 5 mol / L or less, a sufficient effect can be obtained without precipitating from the electrolyte between the semiconductor electrode and the counter electrode without causing an internal short circuit. As for content of the lithium salt in electrolyte composition, 0.5 mol / L or more and 5 mol / L or less are more preferable, 1 mol / L or more and 3 mol / L or less are especially preferable.

The electrolyte composition preferably further contains iodide. As iodide, the iodide of an alkali metal, the iodide of an organic compound, the molten salt of iodide, etc. are mentioned, for example. Examples of molten salts of iodide include heterocyclic nitrogen-containing compounds such as imidazolium salts, pyridinium salts, quaternary ammonium salts, pyrrolidinium salts, pyrazolidinium salts, isothiazolidinium salts and isoxazolidinium salts. Iodide can be used.

Examples of the molten salt of iodide include 1,1-dimethylimidazolium iodide, 1-methyl-3-ethylimidazolium iodide, 1-methyl-3-pentylimidazolium iodide, 1 -Methyl-3-isopentylimidazolium iodide, 1-methyl-3-hexyl imidazolium iodide, 1-methyl-3-isohexyl (branched) imidazolium iodide, 1-methyl-3 -Ethylimidazolium iodide, 1,2-dimethyl-3-propylimidazole iodide, 1-ethyl-3-isopropylimidazolium iodide, 1-propyl-3-propylimidazolium Odoid, pyrrolidinium iodide, etc. are mentioned. These molten salts of iodide can be used individually or in combination of 2 or more types. Moreover, it is preferable that the content is about 0.005 mol / L or more and about 7 mol / L or less in electrolyte solution. By setting it as this range, high ion conductivity can be obtained.

The electrolyte composition may also contain a basic substance such as tert-butyl pyridine (TBP). The basic substance has an effect of suppressing the reverse electron reaction of the tungsten oxide powder.

It is preferable that an electrolyte composition contains iodine in 0.01 mol / L or more and 5 mol / L or less. Iodine is mixed with iodide in the electrolyte composition to act as a reversible redox pair. When the content of iodine is 0.01 mol / L or more, the oxidant of the redox pair is sufficient, and the charge can be sufficiently transported. Moreover, light can be provided to a semiconductor layer efficiently by setting it as 5 mol / L or less. Moreover, it is more preferable that content of iodine is 0.03 mol / L or more and 1 mol / L or less.

The electrolyte composition may be either liquid or gel, and may contain an organic solvent. By containing an organic solvent, since the viscosity of an electrolyte composition can be further reduced, it permeates easily into a semiconductor electrode. As an organic solvent which can be used, For example, Cyclic carbonates, such as ethylene carbonate (EC), a propylene carbonate (PC), and butylene carbonate; Chain carbonates such as dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate; cyclic esters such as γ-butyl lactone, δ-valerolactone and δ-caprolactone; Acetonitrile, methyl propionate, ethyl propionate, and the like. Moreover, cyclic ether, such as tetrahydrofuran and 2-methyl tetrahydrofuran; Chain ethers such as dimethoxyethane and diethoxyethane; Nitrile solvents such as acetonitrile, propionitrile, glutaronitrile, and methoxypropionitrile; and the like. These organic solvents can be used alone or as a mixture of two or more thereof. Moreover, in these, cyclic carbonate or cyclic ester is preferable. Cyclic carbonate or cyclic ester is efficient in charge transfer, and the effect of reducing internal resistance is obtained.

Moreover, although content of an organic solvent is not specifically limited, It is preferable to set it as 90 weight% or less in an electrolyte composition, and it is more preferable to set it as 50 weight% or more and 80 weight% or less.

In addition, it is preferable that the gap size of the support substrate 13 and the conductive catalyst layer 2 serving as a space for injecting the electrolyte composition is in a range of 1.5 to 20 times the thickness of the semiconductor layer. If the gap size between the support substrate 13 and the conductive catalyst layer 2 is less than 1.5 times the thickness of the semiconductor layer, eventually the counter electrode is too close to the semiconductor layer, so that a capacitor accumulated in the semiconductor layer may be transferred to the counter electrode. On the other hand, when it exceeds 20 times, the electrolyte composition layer becomes too thick and internal resistance rises, and there exists a possibility that the capacitor accumulate | stored in a semiconductor layer may become difficult to be transmitted to a counter electrode. Therefore, it is preferable that the clearance size of the support substrate 13 and the conductive catalyst layer 2 used as a space for injecting the electrolyte composition is in the range of 1.5 to 20 times the thickness of the semiconductor layer, and more preferably in the range of 2 to 10 times.

In addition, Raman spectroscopic analysis of the tungsten oxide powder contained in the storage battery of 2nd Embodiment is performed as follows. First, the sealing part on the side of a storage battery is broken, and electrolyte composition (for example, electrolyte solution) is excluded. Subsequently, the glass substrate on the opposite electrode side is removed and the semiconductor layer is exposed. The tungsten oxide particle layer is cut out from the semiconductor layer and washed with pure water, alcohol or an organic solvent to remove the remaining electrolyte solution. Tungsten oxide particles after washing are analyzed by Raman spectroscopy. The measuring method of Raman spectroscopic analysis is as having demonstrated in 1st Embodiment.

According to the storage battery of the second embodiment described above, since the semiconductor electrode including the battery substrate according to the first embodiment is used, the electrical storage performance can be improved, for example, the electrical storage function of 100 C / m 2 or more can be realized. have.

[Example]

Hereinafter, embodiments will be described with reference to the drawings.

(Examples 1 to 15 and Comparative Examples 1 to 3)

First, tungsten oxide (WO ₃ ) powders 1 to 3 were synthesized by the following method.

(Synthesis of Tungsten Oxide (WO ₃ ) Powder 1)

Plasma processing was performed by putting the coarse powder of tungsten oxide whose average particle diameter is 3 micrometers into the plasma flame of 10000 degreeC of center temperature. Tungsten oxide (WO ₃ ) powder 1 having an average particle diameter of 10 nm in terms of BET surface area (average of 100 m 2 / g) was then subjected to quenching at a distance of 1000 m / s or more to the tungsten oxide protruding from the plasma flame. (Sample 1) was prepared.

(Synthesis of Tungsten Oxide (WO ₃ ) Powder 2)

After plasma treatment under the same conditions as in WO ₃ powder 1, heat treatment was performed at 450 ° C. for 50 hours, and the tungsten oxide (WO ₃ ) powder 2 (sample 2) having an average particle diameter of 15 nm in terms of BET surface area (average 56 m 2 / g). Was prepared.

(Synthesis of Tungsten Oxide (WO ₃ ) Powder 3)

After plasma treatment under the same conditions as in WO ₃ powder 1, heat treatment was carried out at 600 ° C. for 1 hour, and tungsten oxide (WO ₃ ) powder 3 (sample 3) having an average particle diameter of 20 nm in terms of BET surface area (average of 42 m 2 / g). Was prepared.

About the obtained samples 1-3, the chart obtained by performing Raman spectroscopic analysis on the conditions demonstrated in 1st Embodiment is shown in FIG. In the chart of FIG. 2, the horizontal axis is Raman shift (cm ⁻¹ ) and the vertical axis is intensity (CPS). As is made clear from Figure 2, the sample 1 was having a third peak to a second peak and the first peak 801㎝ ^{-1, -1} to 695㎝ 269㎝ ^-1. Sample 2 was having a third peak to a second peak and the first peak 805㎝ ^{-1, -1} to 712㎝ 272㎝ ^-1. Sample 3 was having a third peak to a second peak and the first peak 807㎝ ^{-1, -1} to 717㎝ 273㎝ ^-1. Thus, tungsten (WO ₃₎ powder of 1 to 3 and 268 to 274㎝ ^-1 in the range of the second peak, and 800 to 810㎝ ^-1 in the range of the first peak, 630 in the range of ^-1 to 720㎝ oxide Had three peaks.

Subsequently, as shown in Table 1, WO ₃ powders 1 to 3 alone, WO ₃ powders 1 to 3 were coated with Y ₂ O ₃ or CeO ₂ , and the second powder (MgO, Y ₂ O ₃ , C) and TiO ₂ powder were prepared as particles (hereinafter referred to as semiconductor particles) constituting the semiconductor layer. The added amount of the second powder was staging the addition amount (% by mass) when the total amount of the WO ₃ powder and the second powder is 100 mass% in Table 1. The

(Production of battery board)

The glass substrate used was 1.1 mm thick and had a surface resistance of 5 kV / square, and the single side | surface of the glass substrate was coat | covered with the transparent conductive film (ITO).

6.4 g of a binder (EC-100FTP manufactured by Nisshin Kasei Co., Ltd.) was mixed with 3.6 g of the semiconductor particles of Examples 1 to 15 and Comparative Example 1 to prepare a battery electrode material paste. In addition, a paste was prepared by mixing 9 g of semiconductor particles of Comparative Example 2 and 1 g of a binder. 1g of the semiconductor particles of Comparative Example 3 and 9g of the binder were mixed to prepare a paste. Each paste was printed on the transparent conductive film by the screen printing method, and baked at 400-480 degreeC for 30 to 60 minutes. Thus, a semiconductor layer having film thickness, porosity and average pore size shown in Table 2 was formed to obtain a battery substrate of Examples 1 to 15 and Comparative Examples 1 to 3. The film thickness, porosity, and pore average size of the semiconductor layer were measured by the method described in the first embodiment.

The storage battery was obtained by the following method using the obtained battery board of the Example and the comparative example.

The counter electrode which sputter | spattered platinum with 80 nm thickness on the glass substrate provided with a transparent conductive film was used.

A spacer resin having a thickness of 60 µm was disposed in two places through the electrolyte composition injection hole, and surrounded to surround the photoelectrode, and the counter electrode heated at 110 ° C was fitted. The electrolyte composition (electrolyte solution) was injected into the syringe from the electrolyte composition inlet, and the inlet was sealed with a two-liquid curable resin. As the electrolyte composition, 0.5 M (mol) of lithium iodide, 0.05 M of iodine, 0.58 M of t-butylpyridine, and 0.6 M of EtMeIm (CN) ₂ (1-ethyl-3-methylimidazolium dicyanamide) were used in an acetonitrile solvent. . A storage battery was produced by this step.

About the obtained storage battery, the electrical storage performance was measured. The measuring method used an external power supply, charged 640 second at 0.74V with respect to the storage battery of an Example and a comparative example, and computed electrical storage capacity from the electric current value which flows through the connected 510 mA resistance after that. Table 3 shows the obtained power storage capacity (C / m 2) as the power storage function.

As can be seen from Table 3, the storage battery according to the embodiment has a power storage function of 100 C / m 2 or more. In contrast, in the storage batteries of Comparative Examples 1 to 3, the power storage function was lower than 100 C / m 2.

According to at least one embodiment and the embodiment of a substrate for a secondary battery of the above, according to Raman spectroscopic analysis, 268 to the first peak in the range of 274㎝ ^-1, 630 to the second peak in the range of ^-1 and 800 to 720㎝ A tungsten oxide powder having a third peak in the range of 810 cm ^-1 and containing a semiconductor layer having a thickness of 1 µm or more and a porosity of 20 vol% or more and 80 vol% or less, so that a battery having excellent electrical storage performance can be obtained. It can be realized.

(Examples 16 to 20)

Plasma processing was performed by putting the coarse powder of tungsten oxide of an average particle diameter of 1 micrometer into the plasma flame of 11000 degreeC of central temperature. Subsequently, tungsten oxide powder (WO ₃ ) powder was produced by subjecting the tungsten oxide powder protruding from the plasma flame to a quenching of 1200 m / s or more at a distance of 1 m or more.

Then, a heat treatment of one hour at 800 ℃ the tungsten oxide powder was performed, and prepare a BET surface area (average 3.6㎡ / g), the tungsten oxide of the average particle diameter converted from the 230㎚ (WO ₃₎ powder (sample 4) was obtained.

About the obtained sample 4, Raman spectroscopic analysis was performed on the conditions demonstrated in 1st Embodiment. Sample 4 was having a third peak to a second peak and the first peak 807. 3㎝ ^{-1, -1} to 717.2㎝ 273.6㎝ ^-1. Accordingly, sample 4 is 268 to have a third peak in the range of the second peak, and 800 to 810㎝ ^-1 in the range of the first peak 630 to the range of ^-1 720㎝ 274㎝ ^-1 satisfying the conditions Was.

Next, the metal oxide film process was performed about the sample 4. Y ₂ O ₃ was used for the metal oxide. Furthermore, MgO powder was prepared as a 2nd powder. Sample 2, sample 3, sample 4, and the second powder were mixed under the conditions shown in Table 4 to obtain semiconductor particles used in Example 20. In addition, Sample 3 was used for the semiconductor particles of Examples 16 to 19. The added amount of the second powder was staging the addition amount (% by mass) when the total amount of the WO ₃ powder and the second powder is 100% by mass in Table 4.

To 3.6 g each of the semiconductor particles of Examples 16 to 20, 6.4 g of a binder (EC-100FTP manufactured by Nisshin Kasei Co., Ltd.) was mixed to prepare a battery electrode material paste. Each paste was printed on the transparent conductive film or the metal substrate by the screen printing method, and baked at 400-480 degreeC for 30 to 60 minutes. This formed the semiconductor layer which has the film thickness, the porosity, and the average size of the space | gap shown in Table 5, and obtained the board | substrate for storage batteries of Examples 16-20. The film thickness, porosity, and pore average size of the semiconductor layer were measured by the method described in the first embodiment. In addition, when Ti board was used as a support substrate, the insulator was laminated | stacked on the back surface of a support substrate.

As can be seen from Table 5, in Example 20 in which tungsten oxide powders having different particle diameters were combined, the average size of voids could be reduced.

Moreover, the storage battery was obtained by the following method using the storage battery substrate of the obtained Example. Specifically, Table 6 shows the thickness of the spacer resin (corresponding to the gap size between the support substrate 13 and the conductive catalyst layer 2 serving as a space into which the electrolyte is injected), the electrolyte composition, and the conductive catalyst layer. As the counter electrode, a conductive catalyst layer was formed on the same support substrate as that used for the support substrate of the semiconductor layer. In addition, TBP in Table 6 is tert- butyl pyridine.

About the obtained storage battery, the electrical storage performance was measured. The measurement method performed 640 second charge at 0.74V with respect to the storage battery which concerns on Examples 16-20 using the external power supply, and computed electrical storage capacity from the electric current value which flows through the connected 510 ohm resistance after that. The obtained electrical storage capacity (C / m 2) is shown in Table 7 as the electrical storage function.

As can be seen from Table 7, the storage battery according to the embodiment has a power storage function of 100 C / m 2 or more, and further, 3500 C / m 2 or more.

According to at least one embodiment and the embodiment of a substrate for a secondary battery of the above, according to Raman spectroscopic analysis, 268 to the first peak in the range of 274㎝ ^-1, 630 to the second peak in the range of ^-1 and 800 to 720㎝ A tungsten oxide powder having a third peak in the range of 810 cm ^-1 and containing a semiconductor layer having a thickness of 1 µm or more and a porosity of 20 vol% or more and 80 vol% or less, so that a battery having excellent electrical storage performance can be obtained. It can be realized.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Such novel embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the spirit of the inventions. Such an embodiment and its modifications are included in the scope of the invention and the gist thereof, and in the equivalent scope of the invention described in the claims.

Claims (14)

In the Raman spectroscopic analysis, 268 to 274㎝ range ^-1 to the first peak, the tungsten oxide powder has a third peak in the range of the second peak, and 800 to 810㎝ ^-1 in the range of 630 to ^-1 of 720㎝ And a semiconductor layer having a thickness of 1 µm or more and a porosity of 20 vol% or more and 80 vol% or less. The substrate according to claim 1, wherein the BET specific surface area of the tungsten oxide powder is at least 0.1 m 2 / g or more. The board | substrate of Claim 1 or 2 whose thickness of the said semiconductor layer is 5 micrometers or more. The board | substrate of Claim 1 or 2 in which the film is formed in at least one part of the surface of the said tungsten oxide powder. According to claim 4, wherein the coating is Y ₂ O ₃ , TiO ₂ , ZnO, SnO ₂ , ZrO ₂ , MgO, Al ₂ O ₃ , CeO ₂ , Bi ₂ O ₃ , Mn ₃ O ₄ , Tm ₂ O ₃ , A substrate comprising at least one member selected from the group consisting of Ta ₂ O ₅ , Nb ₂ O ₅ , La ₂ O _3, and ITO. The at least one agent according to claim 1 or 2, wherein the semiconductor layer is selected from the group consisting of metal oxide powder, metal boride powder, metal fluoride powder, carbonate powder, carbon powder, metal carbide powder and metal powder. A substrate comprising two powders. The substrate of Claim 1 or 2 whose average size of the space | gap of the said semiconductor layer is 5 nm or more. The board | substrate of Claim 1 or 2 whose average size of the space | gap of the said semiconductor layer is 7 nm or more and 20 nm or less. The board | substrate of Claim 1 or 2 whose thickness of the said semiconductor layer is 5 micrometers or more and 300 micrometers or less, and the porosity of the said semiconductor layer is 40 volume% or more and 70 volume% or less. The substrate of claim 1 or 2,
A counter electrode,
A storage battery comprising an electrolyte composition filled between said semiconductor layer of said substrate for storage battery and said counter electrode. The storage battery according to claim 10, wherein the power storage function is 100 C / m 2 or more. The battery according to claim 10, wherein the electrolyte composition comprises iodine and iodide. The storage battery according to claim 12, wherein the concentration of the iodine in the electrolyte composition is in the range of 0.01 to 5 mol / L, and the concentration of the iodide is in the range of 0.5 to 5 mol / L. The battery according to claim 10, wherein the electrolyte composition comprises tert-butylpyridine.

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